Linear aromatic polyesters



United States Patent Ofiice 3,351,611 LINEAR AROMATIC POLYESTERS AndrJan Conix, Antwerp, Belgium, assignor to Gevaert Photo-Producten N.V.,Mortsel, Belgium, a Belgian company No Drawing. Filed Nov. 8, 1965, Ser.No. 506,854 Claims priority, application Belgium, Dec. 13, 1957, 37,742,Patent 563,173 The portion of the term of the patent subsequent to Nov.9, 1982, has been disclaimed 5 Claims. (Cl. 260-47) This inventionrelates to the production of polymeric materials and particularly oflinear aromatic polyesters and is a continuation-in-part of applicationSer. No. 731,- 874, filed Apr. 30, 1958, now Patent No. 3,216,970.

In my copending application Ser. No. 725,498, now Patent No. 3,028,364,a process is described and claimed for preparing a highly polymericlinear polyester which comprises condensing a di-acid halide of anaromatic dicarboxylic acid, dissolved in an organic liquid which is asolvent for the polyester to be formed, with a metal phenolate of abis-phenol dissolved in a liquid which is immiscible with the solventfor the di-acid halide, the aromatic dicarboxylic acid having thegeneral formula and the bis-phenol having the general formula in whichformulae the hydroxyl group and the carboxyl group may be in the para ormeta position, and each of the R and R represents an alkyl-, aryl-,cycloalkyl-, alkyland aryl-, or halogen-substituted methylene group or acarbon atom which forms part of the cycloaliphatic ring, or onerepresents such group or atom and the other represents a chemical bond,an oxygen atom, a carbonyl group, a sulphonyl group or a saturatedhydrocarbon radical.

According to said copending application, especially high-molecularweights are obtained if the reaction is carried out in the presence of acatalyst, preferably a quaternary ammonium compound.

It is an important advantage of the process according to said copendingapplication that it provides for a method for producing highly polymericlinear polyester according to which the condensation reaction may becarried out at room temperature and at atmospheric pressure, and wherebythe polyester formed is kept in dissolution in the solvent for the acidhalide.

It has now been found that the condensation method according to saidcopending application also can be applied for producing polyesters ofhigh molecular weight, starting from other dicarboxylic acid halides asthose disclosed in said copending application.

It is therefore an object of the present invention to provide new lineararomatic polyesters which dissolve quite well in low-boiling solventsand show high softening temperature. A further object of the presentinvention is to provide a suitable method for the production of suchlinear aromatic polyesters. Still further objects of the presentinvention will appear from the following description and claims.

According to the present invention, highly polymeric linear polyestersare prepared by condensing a di-acid halide of a di-carboxylic acid,dissolved in an organic liquid which is a solvent for the polyester tobe formed, with a metal phenolate of a bisphenol, dissolved in a liquidwhich is immiscible with the solvent for the di-acid halide, thedicarboxylic acid being selected from the group con- HOOG CODE PatentedNov. 7, 1967 Sisting of isophthalic acid, terephthalic acid and fumaricacld, and the bis-phenol having the general formula HO OH wherein thehydroxyl groups are in the para or meta position, and R represents analkyl-, aryl-, cycloalkyl-, alkyland arylor halogen substitutedmethylene group, or a carbon atom which forms part of a cycloaliphaticring.

In this way, polyesters are obtained containing the recurring structuralunits according to the general formula Ia MMeOI wherein R has themeaning given above and A represents a member selected from the group ofthe following bivalent radicals:

In the above formula, the radical R may represent e.g. one of thefollowing bivalent radicals:

- and -CH wherein n and n each represents a positive integer from 1 to7.

The following are bis-phenols, the metal phenolates of which can be usedfor preparing the polyesters according to the present invention:

1, 1- (4,4'-dihydroxy-diphenyl) -cyclohexane,

' l-phenyl-l,1-(4,4'-dihydroxy-diphenyl)methane,

The invention includes polyesters obtained by reacting a mixture of twoor more of the specified diphenolates with one or more of the specifiedaromatic dicarboxylic acid halides or mixtures of two or more of theseacid halides with one or more of the said diphenolates. Especially goodresults are obtained when using a mixture of isoand terephthalic acid.

The invention further includes polyesters obtained by using a mixture ofone or more of the above-mentioned bis-phenolates, with diphenolatessuch as c.g. those derived from hydroquinone, resorcine,di-p-hydroxy-diphenyl, dip-hydroxy-diphenylsulphone,di-p-hydroxy-benzophenone et cetera, or by using a mixture of one ormore of the above mentioned dicarboxylic acid halides with, in minoramounts, halides of other dicarboxylic acids, such as those used in theprocess according to our copending application already identified.

According to the process of the invention, especially high molecularweights are obtained if the reaction is carried out in the presence of asuitable catalyst such as a quaternary ammonium compound, moreparticularly a quaternary ammonium compound which is soluble both inwater and in the organic solvent used for the dicarboxylic acid halide,such as e.g. trimethylbenzylammonium chloride, triethylbenzylammoniumchloride, dimethylethylbenzylammonium hydroxide.

It is an important advantage of the present invention that the reactionmay be carried out at room temperature and at atmospheric pressure. Thenon-miscible solvents separately keep in dissolution the metaldiphenolate and the acid halide together with the polyester formed.

We prefer to use water as the solvent for the metal phenolate and ahalogenated hydrocarbon such as e.g. methylene chloride, chloroform,1,2-dichloro-ethane, 1,1, Z-trichloroethane, sym.-tetrachloroethane,methylchloroform, etc., as common solvent for the acid halide and thepolyester formed during the reaction. Other water immiscible organicsolvents can be used in association with water, such as benzene,toluene, dioxane et cetera.

The diphenolates can be formed by dissolving the diphenols in water inthe presence of equivalent quantities of alkali-metal hydroxides such assodiumor potassium hydroxides. Preferably, the di-acid halide is achloride. Such chlorides can be obtained, e.g. by reaction of therespective dicarboxylic acids with thionyl chloride.

It is a particular advantage of the present invention that it providesfor a polycondensation process according to which aromatic polyesterscan be produced which possess an exceptional high molecular weight asindicated by their intrinsic viscosities ranging from 0.5 to 2.5determined in dichloroethane or tetrachloroethane solution.

In this respect the aromatic polyesters produced according to theprocess of the present invention possess outstanding properties over theformerly proposed polyesters derived from phthalic acids andbis-phenols, such as the film-forming polyesters obtained by reactingisophthaloyl chloride, dissolved in carbontetrachloride, with the sodiumsalt of 2,2'-(4,4-dihydroxydiphenyl)-propane dissolved in water, thepolymer being directly formed at the interface of thewater-carbontetrachloride system in the form of a translucent film. Itis to be noted that the polymer formed is insoluble incarbontetrachloride, so that in this case no solvent for the polymer ispresent in the system. The polyesters prepared according to this methodhave a low molecular weight, as indicated by their low intrinsicviscosity which for the cited polyester is 0.34. Whereas it can beverified that it is not possible to obtain strong and flexible filmsfrom polyesters derived from dicarboxylic acids and bis-phenols if theintrinsic viscosity measured in 1,2-dichloroethane or tetrachloroethanesolution does not exceed 0.5, the value of the intrinsic viscosity ofpolymers which can be used for the production of fibres or films is ofuppermost importance. Particularly valuable films are obtained when theintrinsic viscosities of the polyesters are within the range of 1 to 2.

In accordance with the above considerations, it has been noticed thatthe films produced from isophthaloyl chloride and bis-phenolatesaccording to the abovementioned formerly proposed method show inferiormechanical properties such as e.g. low tensile strength and lowelongation at break; these films, which are moreover very brittle, cantherefore not be used for such applications where a film withoutstanding mechanical qualities is required, e.g. for the applicationas photographic film-base or as wrapping foil in the packaging field.From the polyesters produced according to the process of the presentinvention, however, films can be obtained which advantageously can beused for special purposes e.g. as photographic film-base, the polymersshowing an intrinsic viscosity greater than 0.5, and in many cases,greater than 1.

The polyesters of the present invention are elastic thermoplasticmaterials showing different softening points depending on the nature ofthe diphenol or the di-acid used, but being in any case higher than C.and in most cases higher than 150 C. In this respect, they are superiorto the polyesters obtained e.g. by reacting isophthaloyl chloride withaliphatic glycols, and which have not found technical application onaccount of their low softening points. In consequence of the highsoftening point of the polyesters of the invention, the shaped articlesproduced therefrom possess excellent thermal stability so that evenafter protracted storage of the articles at temperatures of C., theirgood mechanical properties remain unaltered.

Due to the fact that the polyesters of the invention are thermoplastic,they can be worked up from the melt into useful shaped articles byapplying fabrication techniques known in the art such as pressing,moulding or vacuum-forming.

It is a further advantage of the present invention that it provides forhighly polymeric linear polyesters which are soluble in low boilingsolvents. Depending upon the special chemical structure of each of thepolyesters involved, they are soluble in at least one halogenatedhydrocarbon such as methylene chloride, chloroform, 1,2-dichloroethane,sym.-tetrachloroethane, methylchloroform, 1,1,2-trichloroethane etc.Most of the polyesters according to the invention, however, are solublein more than one of the above mentioned halogenated hydrocarbons, andare moreover soluble in other solvents such as benzene, toluene, dioxaneetc. From these solutions films can be cast which are quite transparent,even when obtained after very slow evaporation of the solvent.

The films or fibres prepared from the polyesters according to theinvention by casting them from a solution in low boiling solvents or byextruding them from the melt need not necessarily be stretched and heatset in order to give them useful properties since the unstretched filmsshow good mechanical properties and are especially flexible. If desired,however, the strength of shaped articles such as films and fibresprepared from the polyesters of the invention can be increased bystretching the articlesin one or more directions at room temperature orpreferably at some higher temperature depending on the softening pointof the particular polyester involved.

It is a particular advantage of our invention that it provides forpolyesters from which films can be produced which possess a highdimensional stability when exposed to varying temperatures on relativehumidities. These properties, which are to be ascribed to the highsoftening points and the low water-absorption of the polyesters makethem particularly useful for the manufacture of dimensionally stablephotographic film base. Dimensional stability is an importantrequirement for a film support on which light-sensitive emulsions i.a.for graphic art work are to be coated.

A further advantage of the present invention is that it provides forpolyesters which can be transformed out of the melt or from solutionsinto fibres showing good textile properties.

It is a special aspect of the present invention that the polyestersobtained by condensing fumaroyl dichloride with a bis-phenolate asdefined hereinbefore can be made insoluble in all solvents by heating ata temperature above 200 C. The polyesters of this class can also berendered insoluble by eifectuating the condensation in the presence ofpolymerizable monomers such as vinyl compounds, so that cross linkingoccurs.

Another special aspect of the present invention is that the polyestersobtained from a mixture of isoand terephthaloyl dichloride may beprepared at relatively low price since this mixture is prepared from amixture of isoand terephthalic acid which is commercially available atmarkedly more advantageous conditions than the isoor terephthalic acidseparately and that these polyesters are moreover soluble in halogenatedhydrocarbons with boiling point below 100 C. from which solution clearand transparent films easily can be casted.

The present application is directed to polymers within the scope of theaforegoing disclosure prepared from a diphenol as previously defined anda dicarboxylic acid acid composed of 75-100% isophthalic acid and 250%mers prepared from such diphenols and a dicarboxylic Ser. No. 506,835.

from the polyesters.

ture. The temperature where a large rise in elongation is parative valueand are not to be confused with melting EXAMPLE 1 O l l...

0.1 g. of triethylbenzylammonium chloride in 20 cm.

sodium hydroxide in 40 cm. of water. While agitating added. The rate ofaddition of this solution is regulated in tion mixture is preferablyheld at a temperature between this time, the supernatant aqueous layeris decanted and layer washed with water. Upon pouring the viscous meth-The intrinsic viscosity of the polymer thus obtained and dichloroethane,clear films can be cast which are (175 C.). The films are especiallyuseful as a film base In a three-necked flask, fitted with stirrer,thermomconsisting essentially of fumaric acid alone. Similar polymersprepared from such diphenols and a dicarboxylic terephthalic acid areclaimed in the earlier mentioned parent application Ser. No. 73 1,874,while similar polyacid consisting essentially of terephthalic acid aloneare claimed in a concurrently filed continuing application The followingexamples illustrate the present invention. The softening points areobtained on films prepared The elongation of strips of films subjectedto a load of 0.17 kg./mm. is measured in function of the temperaobservedis taken as the softening temperature. It is to be emphasized that thesetemperatures have only a comtemperatures. In fact, they correspond moreor less with glass transition temperatures.

GOCOOH=CHCO H: J In a three-necked flask fitted with an agitator,thermometer and dropping funnel is brought a solution of of methylenechloride and a solution of 4.6 g. of 1,1-(4,4'-dihydroxydiphenylene)propane and 1.6 g. of solid the mixturevigorously, a solution of 3.1 g. of fumaroyl chloride in 20 cm. ofmethylene chloride is dropwise such a way that all the fumaroyl chlorideis added within a period of 30 minutes. The temperature of the reac- 15and 20 C. After addition of the fumaroyl chloride solution, the mixtureis further agitated for 2 hours. After the very viscous methylenechloride layer washed With water. Upon pouring the viscous methylenechloride ylene chloride layer in a large excess of alcohol, a fibrousprecipitate is formed which can be isolated by filtration.

measured in dichlorethane solution is 0.7 (g./100 cm. From low-boilingsolvents such as methylene chloride characterized by excellentmechanical properties, a low water-absorption and a high heat distortiontemperature for photographic emulsions.

EXAMPLE 2 og-oOo-oo-orhon L CH2 J eter and dropping funnel, is placed4.84 g. of 2,2-.(4,4'- dihydroxy-diphenyl)butane, dissolved in 20.4 cm.of

sodium hydroxide 2.17 N in the presence of mg. of triethylbenzylammoniumchloride dissolved in 20 cm. of methylenechloride. Under cooling thereaction mixture to 20 C. and stirring, there is added over a period of30 minutes a solution of 3.21 g. of fumaroylchloride dissolved in 20 cm.of methylenechloride. The mixture is stirred at room temperature for anadditional 5 hours.

Subsequently, the stirring is stopped and the supernatant aqueous layerdecanted. The organic layer is washed with distilled water and poured inan excess of ethanol. There is obtained 5.5 g. of a nearly white polymerwhich can be isolated by filtration. The softening point of the polymeris found to be about C. The intrinsic viscosity, as determined in1,2-dichloroethane solution, amounts of 0.6 dl./g.

EXAMPLE 3 H 2 H26 CH2 In a three-necked flask, fitted with stirred,dropping funnel and thermometer, is placed 5.36 g. of 1,1-(4,4'-dihydroxydiphenyl)cyclohexane together with 21 cm. of sodium hydroxide1.95 N and 100 mg. of triethylbenzylammoniumchl-oride dissolved in 20cm. of methylenechloride. Under cooling the reaction mixture to 17 C.and under stirring, there is added over a period of 20 minutes 3.06 g.of fumarolylchloride dissolved in 10 cm. of methylenechloride. Themixture is stirred at room temperature for an additional 5 hours.

Subsequently, stirring is discontinued and the supernatant aqueous layerdecanted. The organic layer is washed with water and poured into anexcess of ethanol. The nearly white precipitate is filtered and dried.The softening point of films prepared of this material is found to be C.The intrinsic viscosity of the polyester, as determined in1,2-dichloroethane solution amounts to 0.83 dL/g.

I claim: 7

1. A high molecular weight linear polyester of polybasic acid andpolyhydric alcohol, said polybasic acid consisting essentially offumaric acid, said polyhydric alcohol comprising at least one compoundof the fordrogen and lower alkyl and X is selected from the groupconsisting of:

Y representing the atoms necessary to close a lower cycloaliphatic ringand R and R" each representing a member of the group consisting ofhydrogen, an alkyl radical, a phenyl radical, a cycloalkyl radical, anda haloalkyl radical, alkyl in all instances being lower alkyl, saidpolymer having an intrinsic viscosity of at least about 0.5 dL/g. whenmeasured in a solution of tetrachloroethane, and capable of forming aself-sustaining film.

2. A polyester as in claim 1 having an intrinsic viscosity of about 1-2dl./g. when measured in a solution of tetrachloroethane.

3. A shaped article formed from a linear polyester according to claim 1.

4. A polyester as in claim 1 wherein said bis-phenolic compound is abis-monohydroxyaryl-lower alkane.

5. A high molecular weight, linear polyester having an intrinsicviscosity of at least 0.5 when measured in a solu- 7 8 tion oftetrachloroethane and consisting essentially of 2,854,434 9/1958 Beaman,260--87.5 recurring groups having the following general formula:3,028,364 4/1962 Conix 260-49 CH3 3,216,970 11/1965 ConiX 260-47 -0Q( Joo0cH=cH-oo- 6 FOREIGN PATENTS E 464,762 4/1937 Great Britain.

References Cited I OTHER REFERENCES UNITED STATES PATENTS ruggmlygsg andE/C, pp. 147-150, vol. 51, No. 2, Feb- 2,106,452 1/1938 Bruson 26047 102,595,343 5/1952 Drewitt 260--47 WILLIAM H. SHORT, Primary Examiner.2,708,617 5/1955 Magat 26047 2,808,394 10/1957 Speck 260-793 SAMUELBLECH Exammer- 2,839,508 6/1958 Williams 260--79.3 J. C. MARTIN, L. P.QUAST, Assistant Examiners.

1. A HIGH MOLECULAR WEIGHT LINEAR POLYESTER OF POLYBASIC ACID ANDPOLYHYDRIC ALCOHOL, SAID POLYBASIC ACID CONSISTING ESSENTIALLY OFFUMARIC ACID, SAID POLYHYDRIC ALCOHOL COMPRISING AT LEAST ONE COMPOUNDOF THE FORMULA: